HIRUNDINID.E. 81 



parties, skimming rapidlj in extensive sweeps near 

 the sm-face of the water, and suddenly changing 

 their course backwards and forwards, being all the 

 time busily engaged in capturing the insects upon 

 which they live. Sometimes they may be seen in 

 the streets of towns, or ranging over plains, fields, 

 and gardens, while at intervals they repose, after 

 their exertions, upon the tops of buildings, or upon 

 the branches of trees. Their nests are usually 

 composed of clay or mud, mixed up with straws. 

 They are variously shaped, and generally attached 

 to the exterior of houses or in chimneys, or the 

 interior of hollow trees. Some species construct 

 their nests in holes in the ground, in which case 

 they consist entirely of loose, dry grass, lined with 

 feathers. The eggs are generally five or six in 

 number. 



The migration of the Swallows has now been set 

 beyond a doubt by actual observation, made both 

 on our own shores and on those of the Mediter- 

 ranean, where they are seen taking their departure 

 for the warm regions of Africa, in the autumn, and 

 also making their way back in spring. In crossing 

 the sea, they usually fly singly or in small parties of 

 two or three, and it is remarkable that they arrive 

 on the further side in a state of exhaustion, ap- 

 parently as great as that of other birds of passage, 

 whose power of wing is far inferior. The Channel 

 fishermen state, that in hazy weather the Swallow^s 

 very frequently alight in their boatsj when they are 

 a little way out at sea, so completely fatigued that 

 it is Tvith some difficulty that they muster strength 

 to fly from one end of the boat to the other, when 

 an attempt is made to seize them. In fine calm 

 weather they are often seen to descend upon the 

 smooth surface of the water with their wings widely 

 extended, rising again after a short time seemingly 

 much refreshed by their partial bath. 



The type of the race — 



